FIG. 1 is a cross-sectional view of a prior art torque converter. Turbine dampers are used in torque converters to dampen engine vibrations. For example, as shown in FIG. 1, torque converter 10 includes damper 12. During operation of converter 10, thrust 14 (acting right to left in FIG. 1) is generated on turbine cover 16. Cover 16 transfers the thrust to hub 18, which in turn transfers the thrust to hub 20. In general, hub 20 is in contact with cover 22, or thrust 14 causes hub 20 to contact cover 22. To prevent excessive wear between end 24 of hub 20 and cover 22, thrust washer 26 is disposed between end 24 and cover 22. Typically, washer 26 is constructed of a material having specified wear properties with respect to the materials of construction for hub 20 and cover 22.
In general, washer 26 floats axially with respect to damper 12 and hub 20 unless measures are taken. In some cases, washer 26 is pressed onto hub 20. Unfortunately, press fitting increases fabrication complexity and cost, as well as assembly time. In some cases torque converter 10 is modularly assembled. For example, damper 12 may be shipped separately for later assembly in converter 10. Unfortunately, press fitting requires additional equipment at the site of eventual assembly and thereby, as noted supra, increases complexity, cost, and time. In some cases, washer 26 slides onto hub 20 and additional assembly steps are required to restrain washer 26. For example, cover 22 is assembled to converter 10 to hold washer 26 in place. Unfortunately, the preceding arrangement can hamper modularity. For example, if damper 12 is to be shipped to another site for final assembly in converter 10, damper 12 and washer 26 cannot be preassembled. Instead, the parts must be shipped separately and then mated during final assembly, increasing the cost and complexity of the final assembly.
Hub 20 also can float longitudinally. For example, hub 20 is engaged with one or more splines in converter 10. Unfortunately, the normal and friction forces produced by the spline interfaces may fail to keep hub 20 from moving axially.
To minimize friction and wear between end 24 and washer 26, washer 26 should rotate synchronously with end 24. Unfortunately, in some cases, washer 26 also can float rotationally with respect to hub 20. To prevent this rotation, washer 26 can be pressed, as noted above, with the attendant problems also noted above. Other means (not shown), such as fastening washer 26 to end 24 using rivets, taps, etc. can be used. However, these measures can increase the cost and complexity of the parts and assembly associated with converter 12.
Thus, there is a long-felt need for a thrust washer in a torque converter damper that is easily installed and can be restrained axially and rotationally without press fitting or assembly of ancillary components of the torque converter. Further, there is a long-felt need for a simplified means of preventing axial movement of a hub in a damper for a torque converter. In addition, there is a long-felt need to increase the modularity of torque converter and torque converter damper assembly.